Changes to the way user-modifiable config files are installed.

- Duplicates of the distribution's configuration files are now always
  installed with a .example suffix
- Added --binary-package configure option to toggle configure logic
  specific to the creation of binary packages.
- When not in binary packaging mode, `make install` never overwrites
  existing configure files in case they've been modified.  The previous
  behavior (CMake's default) would only avoid overwriting modified files
  if one consistently uses the same build directory and doesn't reconfigure.
- Fixed an issue with Mac package's pre-install script not preserving ACLs
- Minor cleanup/refactor of the make-mac/rpm-packages scripts

configure

@@ -54,6 +54,7 @@ Usage: $0 [OPTION]... [VAR=VALUE]...
     --with-swig=PATH       path to SWIG executable
 
   Packaging Options (for developers):
+    --binary-package       toggle special logic for binary packaging
     --ignore-dirs=PATHS    paths to ignore when creating source package
                            (semicolon delimited and quoted when multiple)
     --pkg-name-prefix=NAME use the given name as the package prefix instead
@@ -195,6 +196,9 @@ while [ $# -ne 0 ]; do
         --with-swig=*)
             append_cache_entry SWIG_EXECUTABLE      PATH    $optarg
             ;;
+        --binary-package)
+            append_cache_entry BINARY_PACKAGING_MODE BOOL true
+            ;;
         --ignore-dirs=*)
             append_cache_entry CPACK_SOURCE_IGNORE_FILES STRING $optarg
             ;;